Thanks for that, Doc. We appreciate what you do and your help with our members.
I agree, the OP should post a video of their running (barefoot and shod).
If there are core issues, etc., running of any type would be problematic, not just barefoot running. (Did cavemen have core issues?)
If you're talking about impact being the difference, most people who run barefoot impact the ground with a lot less force than someone wearing big, cushioned running shoes that deafen their gait and their feedback from that gait. People who run barefoot ten to run gingerly; people who run shod tend to pound the ground. Some studies have shown that impact forces increase when running shod versus barefoot. Proprioception and sensitivity are lost the moment we cover our feet with anything, right down to a pair of socks. Many here can attest to this, including me. (The reason there are more nerve endings in our feet than anywhere else in the body...well...except one area...is so we can feel the earth, so we can tell where we are at any given time and moment in space.) This loss of feeling contributes to our haphazardly pounding the earth trying to find solid ground, solid footing.
Of course, some would argue that it's not about what is on one's feet or not on one's feet, but rather, the running style being used. We don't learn to run naturally when something covers our feet. We do learn to run naturally when nothing covers our feet. (How could shoes ever be "natural?")
"How one runs probably is more important than what is on one’s feet, but what is on one’s feet may affect how one runs." ~Dr. Daniel Lieberman
This review talks about the evolution of running from unshod to shod, the differences, the outcomes...:
Daniel E. Lieberman. 2012. “
What We Can Learn About Running from Barefoot Running: An Evolutionary Medical Perspective.” Exercise Sport Science Review, 40, 2, Pp. 63-72;
https://scholar.harvard.edu/files/dlieberman/files/2012c.pdf
Barefoot Ken Bob slow-motion on treadmill - YouTube
View attachment 8405▶ 0:40
Aug 17, 2010 - Uploaded by Ken Bob Saxton
Harvard University,
Dr Daniel Lieberman's Skeletal Biology lab Note the subtle fore-foot landing. I'm not ...